hugetlbfs: improve read HWPOISON hugepage

When a hugepage contains HWPOISON pages, read() fails to read any byte of
the hugepage and returns -EIO, although many bytes in the HWPOISON
hugepage are readable.

Improve this by allowing hugetlbfs_read_iter returns as many bytes as
possible.  For a requested range [offset, offset + len) that contains
HWPOISON page, return [offset, first HWPOISON page addr); the next read
attempt will fail and return -EIO.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiaqi Yan <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: James Houghton <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions